More than half a century after his death, we're still searching for the secrets of Albert Einstein's genius. Almost immediately after he died in 1955, the famed physicist's brain was removed from his head, dissected and photographed for study by pathologist Thomas Harvey, who performed the autopsy. Harvey probably didn't have legal permission to remove the brain and preserve it, much less keep it stored in jars in his basement, as he reportedly did for decades, but he did manage to pave the way for scientists to investigate what makes a genius brain tick.

For a new study, researchers from the East China Normal University in Shanghai and Florida State University looked at 14 recently discovered photographs of Einstein's brain. They compared his corpus callosum — the band of fibers that connects the right and the left hemispheres of the brain — with those of ordinary individuals. Einstein died as a 76-year-old, so the researchers compared the photographs of his brain with fMRI data of the brains of 15 men between 70 and 80 years old (right-handed, like Einstein). They also looked at the brains of 52 men between 24 and 30 years old, an age when most people's brains have reached their max weight, and about the age Einstein was during his "miracle year."

Einstein's corpus callosum, they found, was thicker in many subregions than the corpus callousoms of the elderly controls, and thicker in a few subregions than the young controls, which suggests he may have had enhanced connectivity between regions of his brain. Perhaps a small clue to his intellectual prowess? The authors write:

Although the intelligence of human beings cannot be fully explained by regional cortical volumes, our ﬁndings suggest that Einstein’s extraordinary cognition was related not only to his unique cortical structure and cytoarchitectonics, but also involved enhanced communication routes between at least some parts of his two cerebral hemispheres.

Other studies have suggested Einstein's, well, Einstein-iness may have been the result of an unusually high number of brain cells known as glial cells, which surround neurons. This is the first study to look at the genius's corpus callosum. However, the current study does compare pictures of a dead, preserved brain with MRIs of live, working brains, so there may be some limitations in the data. But the authors note that because of the resolution of the MRI, the scans might show the corpus callosum in the control brains as being slightly thicker than it is in real life. Einstein's brain tissue might have shrunk a little during preservation, too, so there's a possiblity the differences could have been even more stark.